I went from stock 255/70/16 to 285/60/18. I know my spedometer and odometer are off but would like to get this corrected.
I have 3:55 LS gears ony my 2wd supercrew, do I need 4:10 gears?
Is a tuner the only way to correct the speedo and odo?

thanks in advance....

 

The computer has to be reprogrammed. You can do this yourself with a tuner, or you could have it done at the dealership. The only reason you might want to change gears is if you have lost power due to taller tires.

 

Your dealer can correct your speedo and adjust your shift points for you. Mine was going to charge $80 for this service, but I ended up getting a custome tuner.

 

Yes, the dealer can correct your speedo and shift points, BUT I believe this is only if you stick on stock sized tires (or something that works out to the same diameter as a stock size tire) This is what my dealer told me, and I have heard it a few times on here.

Superlift makes a thing called the "TruSpeed" I think. You can adjust it for about any tire size there is.

Otherwise you will need a tune.